Android 6.0 on Nexus 6 not allowing swipe from bottom right and left

I just installed Android 6.0 on my Nexus 6 and yet after watching videos of features of Marshmallow, I find that I cannot swipe to activate the camera from bottom right or the phone from bottom left. What am I doing wrong or are there switches I need to activate so these actions function?

if i put android rom, will harmony remote work - left , right , enter open apps.

are there any disadvantages?

Purple line in 2/5 from front from left to right.

After 2 min. play game I found few days ago purple line, after 3-4 minuts it´s gone again. As I understand then it comes with temperature adn leave when temp get lower. Phone rooted. So my phone seems to move to repair? Was that phone what was in market in showcase and as I understut then it was that first phone what arreived to tah shop. Always have in silicone/plastic armory case.